VinnieClaymore

Or do you rather think that this is a matter of simulation? Has the damage been artificially reduced to account for the fact that (also quite artificially) targets cannot jump for cover because of the turn-based system?

I guess this is the case. If the damage was too high you could wipe out a whole group with one grenade. This would lead to massive frustration.

VinnieClaymore

In that case: Would it make sense for some grenades to explode the next turn, and is this moddable? (obviously some grenades detonate on impact, but there are some with a timed fuse, right?)

No, that wouldn't make sense because it wouldn't change anything. If we detonate them at the start of the next turn we still couldn't take cover and if we do it on the end of the turn it is too easy to just run away.

VinnieClaymore

Also: Would it be possible to make explosives throwable? (like tnt, c4, even charges etc.)

As far as I know you can already arm explosives in inventory and throw them afterwards.